Gas-supply-control system



July 8, 1930. E. F. RANDALL 1,770,012

ms SUPPIYJY CONTROL SYSTEM Fild Feb. 26, 1929 miness Patented July 8, 1936 Uifitlitii STAES PATENT OFF ICE EUGENE F. RANDALL, OF BROOKLYN, NEW YORK, 'ASSIGNOR TO THE AMRAD GORPO- I RATION, OF IVZEDFQED MASAOHUSETT$ A CORPORATION OF OHIO GAS-SUPPLY-COI\ TROL SYSTEM Application filed February 26, was. SeriaLNo. 342,877.

The present invention relates to gas supply control systems.

The object of the present invention is to provide an apparatus for controlling the flow of a gas from a supply, particularly for controlling the flow of a rare gas to an evacuated receptacle without leakage or contamination.

With this object in view, the principal feature of the present invention contemplates the provision of supply tubes, the opposed ends of which are closed by porous plugs normally out of contact with each other, and surrounded by a body of liquid to which they are impervious. The liquid normally prevents the flow of gas but when the plugs are moved into contact with each other the gas flows freely through the plugs from one tube into the other.

The drawing is a sectional elevation of an apparatus embodying the features of the present invention, shown as associated with a gas supply.

The invention is herein illustrated and described as embodied in a system for supplying a rare gas, such as helium, to an evacuated receptacle (not shown), for example,

a gaseous conduction rectifying tube.

The supply of helium is contained in a bulb 2 of the usual form which has a sealed projection 4: at its upper end. The bulb is sealed to a supply tube 6 which contains a slug 8 of magnetic material, so that when the apparatus is ready for use the projection 24 may be broken by lifting the slug 8 with a magnet and then letting it fall. The receptacle to be filled with the rare gas is adapted for connection to the tube 10 which connects through a pipe line 12 to any suitable vacuum pump.

The control apparatus is situated between the supply tube 6 and the tube 10, and comprises a container 14 into which the supply tube 6 projects. A tube 16 which forms a continuation of the vacuum line 12 also projects into the receptacle opposite the tube 6. The opposed ends of the tubes 6 and 16 are closed by porous plugs 18 which are pervious to the flow of gas and which are normally maintained out of contact as shown in the drawing. The porous plugs are pref erably of carbon and are provided with accurately ground faces to insure good contact between them when brought into engagement. Received in the container and surrounding the plugs is a body of liquid 20 which does not wet the surfaces of the plugs and to which the latter are impervious. Mercury isthe preferred liquid for this pur pose, not only for its high surface tension but also because it does not wet the surfaces of the plugs, thus effectively sealing the pores of the latter against any flow of gas. In order to permit the proposed surfaces of the plugs to be brought into engagement, the tube 16 which, like the other supply tubes of the apparatus is of glass, is formed with a helical coil 22 to impart flexibility thereto. The end of the container through which the tube 16 passes is closed'by a flexible diaphragm 24 which is preferably of rubber and is cemented to the tube 16 at its central part, the periphery of the diaphragm beingsecured to the container by means of a metal ring 26.

In operation, the receptacle which is to be filled with the rare gas is sealed at the end of the tube 10 and the vacuum pump is operated to exhaust the air therefrom. When the receptacle has been suitably evacuated, the suction line 12 may be closed by a cock 28. This closure of the suction line is necessary only when the pump is at a considerable distance from the receptacle to be evacuated and serves only to conserve the supply of rare gas. During the pumping operation, any air contained in the tube 16 is exhausted therefrom, but there is no effect upon the supply of gas in the bulb 2, the flow of which is prevented by the sealing of the plugs 18 through the interposition of the body of mercury. In order to fill the receptacle with the gas, the tube 16 is moved manually to cause engagement of the opposed surfaces of the plugs 18. The engagement of the plugs forces the mercury from between them and the gas is free to pass therethrough. When the receptacle has been filled to the required pressure, the tube 16 is released and the plugs 18 are automatically separated by the resiliency of the coil 22, whereupon the mercury fills the space between the plugs and closes 5 their surfaces against any further flow of gas, The receptacle may then be sealed ofl and detached from the tube 10.

What is claimed is:

1. A gas control apparatus comprising a body of liquid, opposed gas conduits extending into the liquid, opposed porous plugs closing the conduits and impervious to the liquid,

and means for mounting the conduits having provision for permitting relative movement between them to engage the plugs with each other and permit passage of gas therethrough.

2. A gas control apparatus comprising a conduit adapted to be connected with a gas container, porous means closing the conduit and extending'beyond theend thereof, a second conduit having a porous memberclosing its end and opposed to the porous member of the first conduit,a body of liquid which does not wet the surfaces otthe porous members and in which the latter are immersed, and means for mountingthe conduits to permit the porous members to be moved into engagement with each'other.

3. A gas controllsystem comprising a container, a body of mercury in the container, opposed tubes received in the container, normally separated carbon plugs closing the ends ofthe tubes, and means for mounting the tubes having provision for permitting relative movement between them to engage the opposed surfaces of the plugs with each other.

4:. 'A gas control apparatus comprising gas supply conduits'having adjacent ends provided with material normally penetrable by the gas, and a liquid body impenetrable by the gas adapted to prevent passage of gas when the penetrable material is separated thereby, and to permit the passage of gas when the two ends of penetrable' material are in'contactand the liquid is excluded from therebetween.

5. A method of controlling the flow of gas which consists in providing a two-part gas conduit with adjacent ends closed by plugs of material porous to the gas, surrounding the two ends witha liquid impenetrable by the gas, and moving the ends into and out of contact to permit flow of gas when in contact and to cut off the flow of gas when separated by the liquid.

EUGENE F. RANDALL. 

